Ultrasonic based consumption meters for calculating a consumed quantity of water, heat, cooling, gas or the like, typically has a flow part of metal with a through-going opening that forms a flow passage. Attached to the flow passage is a compartment or housing with a cavity for housing electronic components. The housing serves to protect electronic components, such as a measuring circuit that controls the ultrasonic transducer(s), as well as any additional electronic equipments, such as a calculation circuit for calculating the consumed quantity, a display for displaying a value representing the consumed quantity, a battery for powering the electronic components, a radio communication module, etc.
The fabrication of a flow meter comprises a number of production steps. To provide a flow meter which is cost-efficient to produce, it is necessary to control the fabrication process to limit the number of steps involved.
The international patent application WO 2009/129885 A1 discloses an ultrasonic measuring arrangement comprising a polymer-based measurement tube and housing, where the housing is injection moulded onto the measuring tube to connect them in a seal-less and seam-less manner. While this arrangement possibly is simpler to produce than flow meters based on metallic measurement tubes, it nevertheless suffers from the problem that a number of moulding steps are required in order to produce the assembly.